The present invention relates to niobium and oxides thereof and more particularly relates to niobium oxides and methods to minimize contamination when making at least partially reduced niobium oxide and oxygen reduced niobium.
With the ever-increasing demand for capacitor materials such as tantalum, alternatives to tantalum have become an important priority in order to meet industry demands. Niobium is becoming one of the alternatives to tantalum but, as the industry has realized, niobium is not a complete substitute for tantalum due to niobium not providing the same electrical properties. Accordingly, further developments in the niobium area continue today.
Another alternative to tantalum is niobium metal oxides that have been oxygen reduced, in other words, niobium suboxides such as NbO and the like. The oxygen reduced niobium oxides show considerable promise as providing an additional material that can be used in the formation of capacitor anodes. In order to further satisfy industry demands, several properties of the oxygen reduced niobium oxides should preferably be improved such as the crush strength of the oxygen reduced niobium oxides, as well as efforts to reduce the amounts of contamination that occurs in the manufacturing of the oxygen reduced niobium oxides. In addition, acid leaching is commonly used to reduce the level of contamination occurring when niobium is milled to achieve particular particle sizes. This acid leaching complicates the manufacturing process and adds to additional costs to the manufacturing process.
In addition, the flow property of the oxygen reduced niobium oxides could be further improved to better satisfy industry standards.
Accordingly, there is a need to overcome one or more of the above-described disadvantages.